Saturday, February 17, 2018

So living in the north where it is cold, I have decided to fit heated seat pads to my Cobra's seats. I had said a while ago that any future cars I had with leather seats would always be heated. But in my infinite wisdom decided not to bother for the Cobra - big mistake!

The heat pads for both seats were ordered from Amazon for just £58, including switches, relays and vat. This compares with a 2015 GD price list (which is all I had) at about £300 inc vat. I have decided to fit the switches to the under dash trays to avoid cluttering the dashboard. They have LED indicators showing that the heaters are off or on and at what setting. I may not be able to see the passenger side warning light from the driver's seat, but I should feel the driver's seat warm! This should remind me to check the passenger side.

First the seats were removed by undoing the four nuts and bolts that held each seat in place.

One of the removed seats

A seat base was removed from the seat. The base is held in place by Velcro all around and at the front the leather. I lifted the base from the back, pivoting it towards the front. I then found out that the front was also held in place by some glue, so I had to carefully detach it.

Velcro and glued area on front of seat base

I had expected the back rest to be the most difficult, so I explored this first. The leather was secured with staples at the base.

Staples at base of seat back

These were removed and to my delight the back leather was not stuck to the foam, so the pad can simply be fed up the back and attached with the sticky tape provided.Next, the leather was released from around the back of the seat base. This revealed that the leather was stuck to the foam! So I had to remove the staples from all around the seat base. This was a very time consuming process, because I didn't want to damage the leather. The Velcro was left in place on the base, but staples were removed where necessary.

Staples removed all around

Once all the staples that located the leather had been removed - loads of them, I tackled the delightful job of separating the leather from the foam. The leather was glued fully on to the top of the foam seat base. Once the leather was released, I scraped off the remnants of foam and lightly sanded this to remove any that I had missed.

Cleaned up seat base leather (reverse side)

To get to this point took me about 3 hours for one seat. Now for the other!

I have also ordered some upholstery staples to help me put it all back together, along with some contact adhesive.

When the pads arrive I will tackle the installation and wiring of them.

Thursday, February 01, 2018

I wanted to keep clean lines on the Cobra, so I fitted low profile locks on the bonnet, rather than the traditional locking handles. I felt that my car would look better without the handles and still do. However, from a purely practical point of view, the low profile locks make the bonnet difficult to open. The handles do address this issue.

So I splashed out nearly £120 to address the practicality and thereby sacrificed the looks. I bought a set of handles and locking cams from Europa Spares - a benefit is that the bonnet and boot keys are the same. The four M4 raised head machine screws used to fix the handles came from Kayfast.

The existing locks were removed from the bonnet and the new handles were checked for fit. The existing holes were about 2mm bigger than required and had been squared off for the existing locks, but each hole will be covered completely by the handle fixing plate.

The locating pins on the handle fixing plate were removed, as these and the fixing holes were right next to each other, so would have weakened the fixing point. The underside of the fixing plate were then lightly filed to remove the excess metal left after cutting.

Locating pins removed from inner side of each hole on each fixing plate

The two fixing holes on each fixing plate were marked next to the existing holes, before drilling 4.5mm holes through the bonnet.

Two 4.5mm holes drilled each side of existing hole

The handles were temporarily fitted to the bonnet.

Raised head machine screws used to secure fixing plate

The cams were fitted so that the top edge was the same distance from the bonnet as the top of the locating slot.

Locating slot with escutcheon around it

They were then thinned slightly on the bench grinder so that they located in the bulkhead slots. This was a time consuming and faffy job!

Curved surface of cam thinned down

Once fitted correctly, the machine screws were secured on the underside with nylon nuts and washers.

Bonnet handles fitted in place of locks (a shame)

The boot handle was a straight swap (apart from shortening the square bar) and it looks exactly the same.

Tuesday, January 23, 2018

After trying to buy a hood from GD for some 18 months, they have now announced a hardtop. The Le Mans hardtop, is close to the original Cobra style.

At the time of posting this blog the soft top was still not available. I had a number of other options, to get a hood and I was getting very close to doing this.

The GD soft top (photo by Gardner Douglas)

But I really liked the shape of the Le Mans hardtop, even if you do have to open the rear window in order to open the boot.

427hardtops produce one that looked particularly good. This is a stunning creation, has a window behind the door and stainless steel around the side screens. It may not look like a traditional Cobra hardtop, but still looks very attractive. The design was originally for a Dax Cobra, so it is not an exact fit on the GD. However, 427hardtops have done one for a GD and have another scheduled for February this year. The hardtop comes virtually finished, although it has to be sprayed after that. April looks to be the earliest they could do one for me.

The GD hardtop by comparison is slightly less expensive and looks more like the original. It does however come in kit form, although it can be factory fitted at an extra cost. It is also self coloured, so it should match the gelcoat of the car thereby avoiding the need to have it sprayed (I will need to have the stripes applied separately).

The GD hardtop (photo by Gardner Douglas)

The GD option is slightly shorter than the 427hardtops version. The benefit here is that my fuel filler is at the corner of the boot, rather than an Aston style filler on the rear wing, so it should be easier to access inside the hardtop to fill up. If necessary the fuel filler will be mounted on the C pillar, but this will make the hardtop virtually permanent (this also applies to the 427hardtop). I have been quoted 2 months (late March), although the rear screen production could impact this, so little to chose in timescale.

For me the GD appears to be the better option on balance, but not the only one. So I have ordered a kit and the wait begins. Let's hope that the lead time quoted by GD is met.

Monday, January 22, 2018

After creating the template (see last post), I applied masking tape to the polycarbonate where it would be cut. Then I marked the shape of the template on to the masking tape, including the eye bolt hole centres. A soft cloth was put on the bench to avoid any scratches when cutting. The deflector was cut to the shape of the template using an electric jig saw (use the correct blade and a very slow speed to avoid melting the material - I used speed 2 out of 5). The part cut from the bottom was supported by tape to avoid it snapping when the cut was near to the end.

Polycarbonate cut to shape

Next the four holes for the seat belt anchorages (eye bolts) were drilled. A 4mm hole was drilled first as a pilot hole with a sharp HSS bit. After checking that the pilot holes were in the right place, these were then drilled to size, using a 22mm hole saw.

The edges of the polycarbonate were shaped with a file. Then they were finished off with P80, P400 and P1000 wet n dry paper. Finally the edges were buffed with a foam pad and G10 polishing compound, using the polishing machine. The edges now look like glass.

The fixings, but note that the screws used were 30 mm long

Next the deflector was temporarily fitted on to the roll hoops using just the seat belt eye bolts. The six fixing holes (to locate the P-clips) were marked on to masking tape.

A soft cloth was placed on the bench again to protect the polycarbonate and then the holes were drilled out gradually to 6 mm. It is advisable to drill in to a block of wood to stop the polycarbonate cracking. The deflector was then temporally attached to the roll hoops again, with the P-clips and using M6 x 30 mm button head screws with nylon nuts to make sure they were in the correct position.

Once I was happy with the fit and finish, I removed the protective film from either side of the polycarbonate. Then I wiped the dust from the polycarbonate with a soft cloth.

The deflector was then fixed in its final place. The metal washers go under each screw head and against the outside of the P-clip, with nyloc nuts to stop the deflector working lose (make sure that the plastic washers are against the polycarbonate to reduce the likelihood of cracking). Finally the eye bolts were refitted, along with the seat belts.

Finished wind deflector in place

Does it work? Well it doesn't stand out or detract from the Cobra's lines. It does cut down on the wind behind you head significantly, but it does not totally eliminate it. To do that a hood, a hardtop or a tin top would really solve the problem.

Monday, January 01, 2018

Yes, I am a wuss! Its official. The back draught of cold air and buffeting in the Cobra at this time of year especially (when it is cold) needs taming. I do have a beany hat and a scarf to help keep out the worst of the cold. But most importantly, my wife prefers her hair the right way round!

I researched the subject on the Internet, the Cobra Club Forum and read an article by Paul Hutton (which is really good) in the April 2017 publication of the Snake Torque magazine. From this research I reckoned that there was a way of cutting down the draught on my neck and my passenger's without detracting from the Cobra's lines. So here is what I have done.

Template First the four seat belt eye bolt anchorages were unscrewed from the roll hoops. The wind deflector will fit behind the seats and onto the face of the hoops. Masking tape was applied to the body on the cabin side of the roll hoops to prevent any marks.

Eye bolts removed and masking tape applied

The template was made of hardboard. Duct tape was used to hold the hardboard in place each time it was removed and refitted.

Duct tape on back to hold template

First, the hardboard was marked up to follow the body of the car, then cut with a jig saw. After the first cut, it took a bit of messing about to get the right gap all the way across at the bottom.

Hardboard with first line drawn

Once I had this sorted I marked up the top and sides. The deflector extends 50mm beyond each roll hoop towards the outside of the car. If the deflector extends any further it will scoop up the air passing down the side of the car and channel it behind your head, defeating the whole thing!
Then I marked up a slope - from the top middle of each roll hoop to the outside (about 75mm down from the top), before marking rounded corners. The top corners were a 75mm radius and the bottom corners a 25mm radius (hope this will be ok for the hood or hardtop I get). The template was then cut with a jig saw and planed to get smooth edges. Next I marked the eye bolt holes using a hammer against the hardboard and the mounting hole. The centre was then marked and drilled using a 6mm bit. After checking the holes were in the right place, I drilled them out to 22mm using a step drill. The hole needs to be big enough to clear the shoulder of the eye bolt.

Template cut and eye bolt holes drilled

Finally I put the eye bolts in place finger tight to check they were clear of the hole sides.

Final template with eye bolts in place

I have allowed a 5mm gap between the deflector and the body. This will allow the pressure inside the cabin to be equalised.

Material Laminated glass - this option was beyond my capabilities to work with. It would need to be laminated to avoid it shattering if hit by a stone. Glass is expensive, not easy to cut or drill and is also quite heavy. So this was ruled out.

Perspex - easy to cut and drill. Cheap to buy and widely available. Loses transparency over time, can warp when exposed to UV light and can break in to large shards if hit by a stone. So this too was not an option for an open sports car with no top.

Acrylic sheet - easy to cut and drill. Stable dimensionally, to UV light and stays clear. It has greater break resistance than glass. On impact it breaks in to relatively large pieces, rather than small pieces or shards. Withstands large changes in temperature. Lightweight. Better transparency than glass. Expensive and harder to source.

Solid polycarbonate - similar properties and strength to acrylic sheet. Easier to source and less expensive than Acrylic.

So polycarbonate it was. I have ordered 8mm thick which by all accounts is about right. Any thinner and I risked it vibrating or flexing at speed. Any thicker and it is over doing things. The size of the polycarbonate sheet ordered is 1220mm x 360mm. Prices seem to vary quite alot over time (oil prices?), but Century Plastics in Sheffield seemed to have the best price at around £30 including VAT and carriage and their service is great.

Friday, September 29, 2017

I have never been happy with the sheet steel under dash trays in the GD. In an accident they could be like a blade to the legs or body, stiff and sharp. Ouch!

Metal under dash tray

So, I have decided to replaced them with hardboard, which should give a bit on impact as it is a less stiff material and is more compliant. But hopefully I will never need to test this out.

First I marked lines on the existing trays to show how far they went between the cross braces and dashboard. This material needs to be removed from the new pieces. The two steel trays were then removed and used as templates on the hardboard. The shapes were drawn round in pencil, including the heater duct vent and 12v power outlet. Then the new trays were cut to this line, not forgetting to remove the strip that goes between the dashboard and cross brace. The fixing holes were drilled and the edges rubbed down with sand paper.

New under dash tray cut out from sheet

Each new tray is located by two thin metal tabs (see photo below), which I had fabricated. These tabs are bolted to the tray, then locate between the cross brace and the dashboard. After reconnecting the heater ducts and the 12v power outlet, the trays are then fixed in place with two screws at the front.

Tray fitted. Note the fitted tab,12v outlet and heater duct nozzle

The trays could be painted if required, but I have decided not to do this. The change is simple and would have been a cheaper alternative to the laser cut steel trays! Also it should be much safer too.

Wednesday, August 23, 2017

There was a rattle, but at first I couldn't work out where it came from. Then I found it was from a sun visor. A grub screw on one of the visors had worked loose and fallen out. I couldn't find the screw, so had to buy an M4 x 5mm replacement grub screw from eBay (4 for £1.18).

Apologies for the poor photo. Little grub screw can be seen here

Cooling fan mounting

Two of the four fan mounts had broken after only 1,200 miles, as I previously reported. So I ordered a new fixing kit from Car Builder Solutions for £12 plus postage of £4.20. When I received the parts, the old mountings were removed by undoing the caphead bolts from the rivnuts, which held the fan in place.

Fan mounting point and rivnut can be seen here

The new mountings were then fixed in place.

New mounting fixed with a dab of nut lock

Coolant pipe fixing

I had damaged the jubilee clip which secured the hose from the thermostat to the radiator by tightening it too much. So the coolant leaked from the hose. A sticky mess! A replacement W4 stainless steel clip was bought from eBay for just £1.05. The hose did not have to be removed to do this. The jubilee clip was simply fully loosened, then fixed over the hose (after removing the old clip). Then tightened.

Tuesday, August 22, 2017

There was a Classic Car Show just down the road at Burley in Wharfedale, so I decided to take the Cobra.

My Cobra at the Burley in Wharfedale Classic Car Show

A great show with over 200 other petrolhead's pride and joys. And it was free to show and to come in to look at some mouth watering cars. Look out for the 2018 date in February (the show will be in August).

Friday, August 11, 2017

I have had a coolant leak for some time from the thermostat housing. Unfortunately there is no drain point in the system, so a hose needs to be disconnected. Messy!

First I drained down the system and removed the thermostat housing. This was cleaned up where it mated to the block. Next I applied Hylomar blue sealant to the mating surfaces. After a bit of fiddling I got the thermostat and housing back in place, bolted up and filled ......... but it still leaked. So I repeated the process. It leaked again! So a glass of wine was called for.

After relaxing a bit, I thought of three reasons why this may be happening - the thermostat was not being correctly aligned, the bolts were too long and not allowing the housing to be nipped up or both.

So the next day I checked the bolts and sure enough one was not going in to the block far enough. The bolt was shortened a little to allow it to screw in fully.

Next I fit the rubber thermostat gasket in to the housing, using sealant in the recess where the rubber gasket sits. Then I put two tie wraps through the top of the thermostat and threaded these through the housing. I located the thermostat in place, making sure that the pressure release thingy was in the correct place (there is a recess in the rubber seal). Next I fixed the tie wraps around a bolt to secure the thermostat in the right place and so that it could not be moved whilst fixing. Sealant was applied yet again to the clean mating surface, before the housing was offered up and bolted in place. The tie wraps were removed, the hose reconnected and the jubilee clip tightened. The system was then re-filled gradually, making sure that no air was trapped (tip - get the front of the car higher than the back). Success!

Thermostat housing re-fitted

Radiator fan

Whilst messing about stopping the leak above, I noticed that two of the fan fixings on the driver's side had broken after only 1,200 miles!

Broken fan fixing. Tie wrap can now be seen below it.

What I should have done was to fit tie wraps as well to help stop the mountings moving. I have ordered new fan fixings to replace the broken ones. Guess that is the problem of such a big fan.

Thursday, August 10, 2017

Andy at GD will set up your new GD suspension at no additional cost. My car is a Euro so should only need the dampers setting, as the rest is set as part of the rolling chassis build. The car drives well now, but does 'float' a little over crests in the road and also feels a little unstable particularly at speed on the motorway, which does not instil total confidence when pushing on. The dampers (or shockers) control oscillation of the springs and keep the tyres in contact with the road. So this is what I needed to sort out to address the minor handling issues.

I didn't really want to take the car to the factory, as it is a 2.5 hour drive each way and I have no weather gear to combat the vaguaries of the British summer. A quick call to Andy and he explained the way to adjust the dampers and that it should correct the issues above. The dampers are set using just one knob for both the compression and rebound. If I made a pigs ear out of it, there is no real harm done as it can be corrected!

Andy knows the feel of the cars and the changes needed to correct the symptoms. It also depend on the weight of the driver, passenger and junk/tools etc carried in the boot (if a lot of weight in the boot you may need more clicks at the rear). He suggested that damper settings of around 4-6 clicks clockwise are likely to be about right, but that I may need to amend this to my preference. No change is required to the spring rates or toe. However, for the track more clicks may be required e.g 12/13!

The first job is to set the ride height. Mine is set to clear local speed bumps (see a previous post).

Collar for ride adjustment can be seen here

This is achieved by adjusting the collars up (using a C spanner) at the bottom of the springs.

The lower the car the less it will roll in corners (lowers the centre of gravity) and the better it will handle, but the car is more likely to come into contact with speed humps (legal limit for a speed bump on a public road is 4" I think) or raised road surfaces/metalwork - so you have been warned!

Next I needed to back off all four dampers fully (they were set to 5 clicks at the factory) - turning the knurled knob fully anti-clockwise, so that the knob will not turn any further (don't force it). You should be able to do this with the wheels on. The knobs are at the bottom of the dampers - on the inside at the front and on the leading edge at the rear.

Front nearside damper knurled knob (faces away from wheel)

Rear nearside damper knob (faces front of car)

Then turn the knob, say 6 clicks clockwise (which is one full rotation of the knob). For road use/touring you do not want the car to be too stiff or it will be uncomfortable and thump over every road imperfection. I set mine to 6 clicks. With 7 clicks it handled well but was a tad too hard. If you have a roll bar fitted the setting is likely to vary

Now the good bit. Once adjusted, test the car on your favourite road 😆. If it is not quite right, further adjustments can be made. Extra clicks will firm up the dampers, backing it off will reduce the damping effect. Note, this is not the spring rate, but the speed at which the dampers move and allow the car to roll in corners, control the car over undulations and dive (or not) under braking.

Tuesday, August 08, 2017

We had a drop of rain on the North York Moors Cobra Club run. If we went fast enough the rain went over the top of us, unfortunately I had not sealed the windscreen stanchions properly and it dripped in to the passenger foot well. Not too bad as it was on to the passenger's legs and not mine!

Gap down side of stanchion let water in

In addition the rubber seal of the windscreen had a kink in it, so GD had supplied a new one without the fault.

Kink can be seen in photo above

So I had to remove the screen. This is a time consuming job, as you need to remove the sun visors, mirrors, wind wings, centre bracket, before unscrewing and lifting out. But a tip, remove the passenger under dash tray and one of the bigger gauges on the dashboard. Now you can get your hand in to remove the nuts holding in the central screen bracket. This is a lot easier than removing the whole dash!

Whilst the screen was off I re-did the drivers side stanchion sealing. The escutcheons needed removing to do this job properly. The new rubber seal went on easier with some Vaseline to aid sliding in to the channel on the under side of the windscreen.

Stanchion re-sealed

New rubber seal without the kink!

So, hopefully dry legs now. Not that it goes out in the rain .... well it is not planned anyway!

Page views since Dec 2014

Search This Blog

How to use this blog

This is a record of my Cobra sports car build. If you want to create a Cobra too, this step by step diary may help you or simply give you some advice on how to go about it.

If you are interested in the build process, then just look at the posts in chronological order. The blog shows the most recent posts first. Look out for the 'Older posts' link at the bottom of any page.

If you are interested in a specific area of the build e.g. brakes, then click on 'Brakes' under 'Build process' and you will just see stuff about the brakes. Do look at the "Things that went wrong" category to see lessons that I learned the hard way during the build. Where possible I have added a note to the relevant post too. Remember that the posts are shown with the newest first.

Should you want to see other people's builds, suppliers or other elements please just click on the appropriate link provided.

Also don't forget to get your free email which will tell you when there is anything new.